Management of an arrhythmia requires precise diagnosis of the type of arrhythmia, and electrocardiography is essential; underlying causes such as heart failure require appropriate treatment. 
Ectopic beats
If ectopic beats are spontaneous and the patient has a normal heart, treatment is rarely required and reassurance to the patient will often suffice. If they are particularly troublesome, beta-blockers are sometimes effective and may be safer than other suppressant drugs.
Atrial fibrillation
Atrial fibrillation can be managed by either controlling the ventricular rate or by attempting to restore and maintain sinus rhythm.Ventricular rate can be controlled with a beta-blocker or diltiazem [unlicensed indication], or verapamil. If rate control is inadequate during normal activities, digoxin can be added; in those who require additional rate control during exercise, a combination of diltiazem or verapamil with digoxin should be used, but care is required if ventricular function is diminished. Digoxin is usually only effective for controlling ventricular rate at rest, therefore digoxin monotherapy should only be used in predominantly sedentary patients; digoxin is also used if atrial fibrillation is accompanied by congestive heart failure.
Sinus rhythm can be restored by electrical cardioversion, or pharmacological cardioversion with an intravenous anti-arrhythmic drug e.g. propafenone, flecainide, or amiodarone. If necessary, sotalol or amiodarone can be started 4 weeks before electrical cardioversion to increase success of the procedure. If drug treatment is required to maintain sinus rhythm, a beta-blocker is used. If a standard beta-blocker is not appropriate or is ineffective, an oral anti-arrhythmic drug such as sotalol flecainide, propafenone, or amiodarone, is required.
In symptomatic paroxysmal atrial fibrillation, ventricular rhythm is controlled with a beta-blocker. Alternatively, if symptoms persist or a beta-blocker is not appropriate, an oral anti-arrhythmic drug such as sotalol, flecainide, propafenone, or amiodarone can be given.
All haemodynamically unstable patients with acute-onset atrial fibrillation should undergo electrical cardioversion. Intravenous amiodarone, or alternatively flecainide, can be used in non-life-threatening cases where electrical cardioversion is delayed. If urgent ventricular rate control is required, a beta-blocker, verapamil, or amiodarone can be given intravenously.
All patients with atrial fibrillation should be assessed for their risk of stroke and the need for thromboprophylaxis. Anticoagulants are indicated for those with a history of ischaemic stroke, transient ischaemic attacks, or thromboembolic events, and those with valve disease, heart failure, or impaired left ventricular function; anticoagulants should be considered for those with cardiovascular disease, diabetes, hypertension, or thyrotoxicosis, and in the elderly. Anticoagulants are also indicated during cardioversion procedures. Aspirin is less effective than warfarin at preventing emboli, but may be appropriate if there are no other risk factors for stroke.
Atrial flutter
The ventricular rate at rest can sometimes be controlled with digoxin. Reversion to sinus rhythm (if indicated) may be achieved by cardiac pacing or appropriately synchronised d.c. shock. Alternatively, amiodarone may be used to restore sinus rhythm, and amiodarone or sotalol to maintain it. If the arrhythmia is long-standing a period of treatment with anticoagulants should be considered before cardioversion to avoid the complication of emboli.
Paroxysmal supraventricular tachycardia
In most patients this remits spontaneously or can be returned to sinus rhythm by reflex vagal stimulation with respiratory manoeuvres, prompt squatting, or pressure over one carotid sinus (important: pressure over carotid sinus should be restricted to monitored patients—it can be dangerous in recent ischaemia, digitalis toxicity, or the elderly).
If vagal stimulation fails, intravenous administration of adenosine is usually the treatment of choice. Intravenous administration of verapamil is useful for patients without myocardial or valvular disease For arrhythmias that are poorly tolerated, synchronised d.c. shock usually provides rapid relief.
In cases of paroxysmal supraventricular tachycardia with block, digitalis toxicity should be suspected. In addition to stopping administration of the cardiac glycoside and giving potassium supplements, intravenous administration of a beta-blocker may be useful. Specific digoxin antibody is available if the toxicity is considered life-threatening .
Arrhythmias after myocardial infarction
In patients with a paroxysmal tachycardia or rapid irregularity of the pulse it is best not to administer an antiarrhythmic until an ECG record has been obtained. Bradycardia, particularly if complicated by hypotension, should be treated with 500 micrograms of atropine sulphate given intravenously; the dose may be repeated every 3–5 minutes if necessary up to a maximum total dose of 3 mg. If there is a risk of asystole, or if the patient is unstable and has failed to respond to atropine, adrenaline should be given by intravenous infusion in a dose of 2–10 micrograms/minute, adjusted according to response. For further advice, refer to the most recent recommendations of the Resuscitation Council (UK) available at www.resus.org.uk.
Ventricular tachycardia
Drug treatment is used both for the treatment of ventricular tachycardia and for prophylaxis of recurrent attacks that merit suppression. Ventricular tachycardia requires treatment most commonly in the acute stage of myocardial infarction, but the likelihood of this and other life-threatening arrhythmias diminishes sharply over the first 24 hours after the attack, especially in patients without heart failure or shock. Lidocaine (lignocaine) is the preferred drug for emergency use. Other drugs are best administered under specialist supervision. Very rapid ventricular tachycardia causes profound circulatory collapse and should be treated urgently with d.c. shock.
Torsade de pointes is a form of ventricular tachycardia associated with a long QT syndrome (usually drug-induced, but other factors including hypokalaemia, severe bradycardia, and genetic predisposition are also implicated). Episodes are usually self-limiting, but are frequently recurrent and can cause impairment or loss of consciousness. If not controlled, the arrhythmia can progress to ventricular fibrillation and sometimes death. Intravenous infusion of magnesium sulphate is usually effective. A beta-blocker (but not sotalol) and atrial (or ventricular) pacing can be considered. Anti-arrhythmics can further prolong the QT interval, thus worsening the condition.
Ectopic beats
If ectopic beats are spontaneous and the patient has a normal heart, treatment is rarely required and reassurance to the patient will often suffice. If they are particularly troublesome, beta-blockers are sometimes effective and may be safer than other suppressant drugs.
Atrial fibrillation
Atrial fibrillation can be managed by either controlling the ventricular rate or by attempting to restore and maintain sinus rhythm.Ventricular rate can be controlled with a beta-blocker or diltiazem [unlicensed indication], or verapamil. If rate control is inadequate during normal activities, digoxin can be added; in those who require additional rate control during exercise, a combination of diltiazem or verapamil with digoxin should be used, but care is required if ventricular function is diminished. Digoxin is usually only effective for controlling ventricular rate at rest, therefore digoxin monotherapy should only be used in predominantly sedentary patients; digoxin is also used if atrial fibrillation is accompanied by congestive heart failure.
Sinus rhythm can be restored by electrical cardioversion, or pharmacological cardioversion with an intravenous anti-arrhythmic drug e.g. propafenone, flecainide, or amiodarone. If necessary, sotalol or amiodarone can be started 4 weeks before electrical cardioversion to increase success of the procedure. If drug treatment is required to maintain sinus rhythm, a beta-blocker is used. If a standard beta-blocker is not appropriate or is ineffective, an oral anti-arrhythmic drug such as sotalol flecainide, propafenone, or amiodarone, is required.
In symptomatic paroxysmal atrial fibrillation, ventricular rhythm is controlled with a beta-blocker. Alternatively, if symptoms persist or a beta-blocker is not appropriate, an oral anti-arrhythmic drug such as sotalol, flecainide, propafenone, or amiodarone can be given.
All haemodynamically unstable patients with acute-onset atrial fibrillation should undergo electrical cardioversion. Intravenous amiodarone, or alternatively flecainide, can be used in non-life-threatening cases where electrical cardioversion is delayed. If urgent ventricular rate control is required, a beta-blocker, verapamil, or amiodarone can be given intravenously.
All patients with atrial fibrillation should be assessed for their risk of stroke and the need for thromboprophylaxis. Anticoagulants are indicated for those with a history of ischaemic stroke, transient ischaemic attacks, or thromboembolic events, and those with valve disease, heart failure, or impaired left ventricular function; anticoagulants should be considered for those with cardiovascular disease, diabetes, hypertension, or thyrotoxicosis, and in the elderly. Anticoagulants are also indicated during cardioversion procedures. Aspirin is less effective than warfarin at preventing emboli, but may be appropriate if there are no other risk factors for stroke.
Atrial flutter
The ventricular rate at rest can sometimes be controlled with digoxin. Reversion to sinus rhythm (if indicated) may be achieved by cardiac pacing or appropriately synchronised d.c. shock. Alternatively, amiodarone may be used to restore sinus rhythm, and amiodarone or sotalol to maintain it. If the arrhythmia is long-standing a period of treatment with anticoagulants should be considered before cardioversion to avoid the complication of emboli.
Paroxysmal supraventricular tachycardia
In most patients this remits spontaneously or can be returned to sinus rhythm by reflex vagal stimulation with respiratory manoeuvres, prompt squatting, or pressure over one carotid sinus (important: pressure over carotid sinus should be restricted to monitored patients—it can be dangerous in recent ischaemia, digitalis toxicity, or the elderly).
If vagal stimulation fails, intravenous administration of adenosine is usually the treatment of choice. Intravenous administration of verapamil is useful for patients without myocardial or valvular disease For arrhythmias that are poorly tolerated, synchronised d.c. shock usually provides rapid relief.
In cases of paroxysmal supraventricular tachycardia with block, digitalis toxicity should be suspected. In addition to stopping administration of the cardiac glycoside and giving potassium supplements, intravenous administration of a beta-blocker may be useful. Specific digoxin antibody is available if the toxicity is considered life-threatening .
Arrhythmias after myocardial infarction
In patients with a paroxysmal tachycardia or rapid irregularity of the pulse it is best not to administer an antiarrhythmic until an ECG record has been obtained. Bradycardia, particularly if complicated by hypotension, should be treated with 500 micrograms of atropine sulphate given intravenously; the dose may be repeated every 3–5 minutes if necessary up to a maximum total dose of 3 mg. If there is a risk of asystole, or if the patient is unstable and has failed to respond to atropine, adrenaline should be given by intravenous infusion in a dose of 2–10 micrograms/minute, adjusted according to response. For further advice, refer to the most recent recommendations of the Resuscitation Council (UK) available at www.resus.org.uk.
Ventricular tachycardia
Drug treatment is used both for the treatment of ventricular tachycardia and for prophylaxis of recurrent attacks that merit suppression. Ventricular tachycardia requires treatment most commonly in the acute stage of myocardial infarction, but the likelihood of this and other life-threatening arrhythmias diminishes sharply over the first 24 hours after the attack, especially in patients without heart failure or shock. Lidocaine (lignocaine) is the preferred drug for emergency use. Other drugs are best administered under specialist supervision. Very rapid ventricular tachycardia causes profound circulatory collapse and should be treated urgently with d.c. shock.
Torsade de pointes is a form of ventricular tachycardia associated with a long QT syndrome (usually drug-induced, but other factors including hypokalaemia, severe bradycardia, and genetic predisposition are also implicated). Episodes are usually self-limiting, but are frequently recurrent and can cause impairment or loss of consciousness. If not controlled, the arrhythmia can progress to ventricular fibrillation and sometimes death. Intravenous infusion of magnesium sulphate is usually effective. A beta-blocker (but not sotalol) and atrial (or ventricular) pacing can be considered. Anti-arrhythmics can further prolong the QT interval, thus worsening the condition.
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